Figure 1
Lyon metro network.
Figure 2
Geological profile.
Figure 3
Geological profile.
Figure 4
Tunnel, shield, and liner parameters.
Table 1
Tunnel parameters.
| Section | H (m) | L (m) | C/D - | Hw (m) | Dext (m) | Dint (m) | D/2 (mm) | Φext (m) | Φint (m) | Liner width (cm) | Liner thickness (cm) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| P1-S1 | 16.9 | 7.0 | 2.20 | 8.30 | 6.27 | 6.24 | 15 | 6.0 | 5.3 | 100 | 35 |
Figure 5
Evolution of settlements.
Figure 6
Lateral movements.
Figure 7
3D numerical model.
Figure 8
Components of the interface constitutive model.
Table 2
Mohr–Coulomb parameters.
| Layer | Depth - | Shear (G) | Bulk (K) | Weight (g) | Cohesion (c’) | Friction (j’) | Dilatancy (y’) |
|---|---|---|---|---|---|---|---|
| m | MPa | MPa | kN/m3 | KPa | ° | ° | |
| Fill | 0–7 | 2.92 | 7.8 | 18 | 30 | 30 | 17 |
| Beige silt | 7–10 | 2.74 | 7.3 | 19.5 | 12 | 33 | 20 |
| Ocher silt | 10–13 | 2.74 | 7.3 | 21 | 15 | 25 | 14 |
| Grey clay | 13–15 | 1.57 | 4.2 | 16.5 | 35 | 27 | 15 |
| Grey sand | 15–17.5 | 10.50 | 28 | 21 | 5 | 35 | 21 |
| Purplish clay | 17.5–20 | 5.16 | 13.8 | 18.5 | 35 | 27 | 15 |
| Sand and gravel | 20–50 | 10.50 | 28 | 21 | 0 | 34 | 20 |
Figure 9
Performance of FLAC-3D interface element: (a) tangential displacement on the interface element (units: m) and (b) ground movements around the tunnel cavity.
Table 3
The properties of grout in modeling.
| Grout | Unit weight (kN/m3) | Young’s modulus (MPa) | Poisson ratio (-) | Bulk modulus (K) (MPa) | Shear modulus (G) (MPa) | K/G (-) |
|---|---|---|---|---|---|---|
| Fluid state | 18 | 5 | 0.495 | 166.7 | 1.7 | 99.7 |
| Solid state | 18 | 30 | 0.20 | 16.7 | 12.5 | 1.3 |
Figure 10
Contour of vertical displacements after complete installation of the shield (units: m).
Figure 11
Transverse settlement troughs at different phases: (a) simulations and (b) field data.
Figure 12
Final surface settlement troughs.
Figure 13
Transverse settlement troughs.
Figure 14
Longitudinal ground settlements: (a) field data and (b) simulations
Figure 15
Lateral movements: (a) field data and (b) simulations.
Figure 16
Final lateral movements,